How can something be three and one at the same time? Mathematics and logic will tell you that three cannot equate to one, but when understanding the person and identity of our God, there can be no better explanation.
The Trinity is never mentioned in the Bible, but the concept of God existing as three and one is written all over His Word. When God created the world, He always said, "Let us..." implying that He exists as multiple beings. But Deuteronomy 6:4 declares "Hear, O Israel: The Lord our God, the Lord is one."
Our God is one God, but exists in three characters -- Yahweh or God the Father, Jesus or God the Son, and the Holy Spirit. In the beginning was the Word and the Word was with God and the Word was God. That Word was Jesus, and Jesus existed as the Father was forming the earth, and, as the Spirit of God, hovered over the waters of the earth (Genesis 1:2).
This is not an example of the Bible contradicting itself, but rather its completeness in painting a limited picture of an unlimited God. We can never completely understand God because He is beyond human comprehension. In Matthew 11:25, Jesus declares "I thank you, Father, Lord of heaven and earth, that you have hidden these things from the wise and understanding and revealed them to little children."
There is no understanding God fully in our limited thinking, but our goal is to know more and more about the loving God who rules over all the earth. Although there is no complete illustration that shows us God as the Trinity, here are some illustration that can help us understand how God can exist as three and as one.
Water, Steam and Ice
Water can exist in three different states, as solid, liquid and gas, but in all these forms, water is still water. In the same way, God can exist in three different forms, but in any form He is still God. God the Father, God the Son and God the Holy Spirit all exist as separate forms, but are all equally God. No one is higher than the other.
A Basketball Team
If you've ever played basketball, it will be clear to you how important it is for a team of five act together in complete unity and be as one. Although there is a center, two forwards and two guards, there is one team.
God is like a basketball team in this sense, and perfectly illustrates to us what unity is. Unity is not similarity because God exists in three diverse characters which work together as one.
Humans
We exist as one person, but at the same time we exist in three forms. Everyone is composed of body, soul and spirit. If you don't have a body then you're probably a ghost, and if you don't have a spirit then you're probably dead.
The body cannot exist without the soul and spirit, and God cannot exist as just one character. He is all three at the same time.
